Medical electrode glove with partially insulating layer

ABSTRACT

A medical device treats diseases of the hand, wrist, and arm, including osteoarthritis and osteoarthrosis of the joints of the human hand. The medical device includes a multi-layer glove system, an arm wrap, a signal generator, lead wires, and a garment. The multi-layer glove system serves as the treatment electrode. One of the layers electrically insulates a portion of the hand, allowing a different portion to make electrical contact with a conductive layer. The arm wrap serves as the return electrode. The signal generator produces a specific, spike shaped electrical signal, together with the multi-layer glove system, at the treatment site. The device can reduce pain and increase joint function of the treated joints.

BACKGROUND

The present invention generally relates to treating joints, such as ahuman hand and wrist.

The hand and wrist are affected by a number of diseases includingseveral forms of arthritis, such as rheumatoid arthritis andosteoarthritis. Rheumatoid arthritis is a chronic, systemic inflammatorydisease of unknown etiology characterized by the manner in which itinvolves the joints. The onset of the disease may be acute or insidious.Articular involvement is manifested clinically by pain, stiffness, lossof motion, deformity of joints, and the signs of inflammation.Rheumatoid arthritis affects many joints, most commonly the hands andwrists.

Osteoarthritis or osteoarthrosis is a degenerative joint disease, whichcommonly affects both axial and peripheral diarthrodial joints inhumans. The effects of this increase steadily with age, so it is morecommon in the elderly. Osteoarthritis causes progressive deteriorationand loss of articular cartilage from the surfaces of joints, andreactive changes at joint margins and in the underlying bone. Symptomsthat are treatable include joint pain, stiffness, limitation of motion,and synovitis or joint inflammation. The treatments for rheumatoidarthritis and osteoarthritis of the hand and wrist are distinctlydifferent, often individualized, and may include application of anelectrical signal to the joints.

In U.S. Pat. No. 5,273,033 to Hoffman, which is specificallyincorporated by reference herein, a device is shown that is said todecrease pain and improve joint function in patients with osteoarthritisof the knee.

SUMMARY

Embodiments are disclosed for a medical device that treats diseases ofbones and joints, including the hand, wrist, and arm, such as rheumatoidarthritis and osteoarthritis. In one embodiment, the medical deviceincludes a multi-layer glove system, an arm wrap, a signal generator,lead wires, and a garment. The multi-layer glove system serves as atreatment electrode. One of the layers electrically insulates a portionof the hand, allowing a different portion of the hand to make electricalcontact with a conductive layer. The arm wrap serves as a returnelectrode. The signal generator produces a desired waveform, such as aspike shaped electrical signal, through the multi-layer glove system, atthe treatment site. The garment has lead wires for connecting themulti-layer glove system and arm wrap to the signal generator. Thegarment keeps the lead wires in place and helps prevent the user frombecoming tangled in the wires.

When a patient operates the medical device, a desired electrical signalis delivered to the joints of the hand and elbow. The system can reducepain and increase the function of the treated joints. Other features andadvantages will become apparent from the following detailed description,drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of various embodiments of the presentinvention, reference is now made to the following descriptions taken inconnection with the accompanying drawings in which:

FIG. 1 is a pictorial view of a medical device according to anembodiment of the inventions.

FIG. 2 is a side view of an arm wrap as worn.

FIGS. 3A-3C are pictorial views of an insulating inner glove, aconductive glove, and a protective outer glove according to oneembodiment.

FIG. 4A is a pictorial view of the protective outer glove of FIG. 3C,with a current-interrupting safety feature.

FIG. 4B is an exploded, partial cross-sectional side view of themulti-layered glove system as worn.

FIG. 5 is a front plan view of a signal generator according to oneembodiment.

FIG. 6 is a bottom plan view of the signal generator of FIG. 5.

FIG. 7 is an example of a voltage waveform illustrating characteristicsof the electrical treatment signal under no load conditions as producedby an embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 illustrates an embodiment of a medical device 10 that includes amulti-layer glove system (shown by 200, 300, and 400), an arm wrap 101,a signal generator 50, a garment 103, and at least one lead wire 104.The user wears the glove system on the hand, arm wrap 101 around theupper arm, and garment 103 like a jacket. The garment has a pocket 105for holding signal generator 50. The signal generator, glove system, thepatient's hand and wrist, the patient's arm, and the arm wrap form anelectrical path. When used, signal generator 50 provides periodicelectrical signals that pass to the glove system, up the patient's arm,through the arm wrap 101, and back to the signal generator to try toalleviate the effects of bone and joint diseases.

In one embodiment, garment 103 is a jacket worn over a patient'sclothing. Garment 103 may be made of a variety of materials, includingtraditional clothing fabric or a woven polymer fabric and can bedesigned for comfort. Garment 103 has at least one lead wire 104 sewninto the material of garment 103, but could have two lead wires, one fortreating the left side of the patient's body and one for treating theright side.

Lead wire 104 has a signal generator connection 106, an arm wrapconnection 107, and a glove connection 108. Signal generator connection106 may be a keyed shape to ensure proper connection to the signalgenerator, also described below. Arm wrap connection 107 and gloveconnection 108 may be metal snaps, although other releasable connectionmechanisms may be used. The connections may be color-coded to ensureconnection to the proper component.

Lead wire 104 is attached to, or held within, garment 103 so that whengarment 103 is worn, each connection is held for easy attachment to thedesired components of medical device 10. In addition, garment 103 helpsto prevent the patient from becoming entangled in the lead wires. Signalgenerator connection 106 is held near pocket 105 for attachment tosignal generator 50 in the pocket. Arm wrap connection 107 is held neara point about half way between the elbow and shoulder of the patient forattachment to arm band 101. Garment 103 has a flap 109 to allow thepatient easy access to arm wrap 101. Glove connection 108 is held nearthe wrist for attachment to the multi-layer glove system. A like designwould apply to a second lead wire (not shown) for use on the other sideof the body.

Garment 103 may have snaps or other releasable connection mechanisms atthe locations recited above. The snaps may be used to hold the variousconnections when not in use. For example, a snap 110 is located near thewrist of the patient and may hold glove connection 108 when themulti-layer glove system is not connected.

FIG. 2 illustrates a side view of arm wrap 101 worn on the patient's armabout half way between the elbow and the shoulder. Arm wrap 101 has alead wire connection 111, which connects to arm wrap connection 107 oflead wire 104 of FIG. 1. Arm wrap 101 has at least one electricallyconductive surface, which is placed in contact with the skin of theupper arm. The electrically conductive surface may be made from silverplated nylon. Other electrically conductive surfaces, such astraditional transcutaneous electrical nerve stimulation electrode pads,may be used.

FIGS. 3A, 3B, and 3C illustrate three separate components of themulti-layer glove system. All three components of the multi-layer glovesystem are worn simultaneously and in layers. Referring to FIG. 3A, anelectrically insulating inner glove 200 is worn on a hand of thepatient. The finger-covering members of insulating inner glove 200 areshortened and open-ended. Thus, when insulating inner glove 200 is worn,the skin covering the interphalangeal joints (the “outer knuckles”) ofthe hand is exposed, but insulating material covers the palm and backportions of the hand and wrist, including the skin covering themetacarpophalangeal joints (the “inner knuckles”) of the fingers andthumb. For example, an exposed finger portion 201 protrudes from ashortened, open-ended finger-covering member 202. Insulating inner glove200 is made of an electrically insulating material, such as vinyl,neoprene, or polyurethane, and should be made comfortable to wear evenover many hours.

Referring to FIG. 3B, an electrically conductive glove 300 is worn onthe hand of the patient, over the previously fit insulating inner glove200 of FIG. 3A. Conductive glove 300 makes electrical contact with theexposed finger portions that protrude from the shortened finger-coveringmembers of insulating inner glove 200. However, conductive glove 300does not make electrical contact with the palm and back portions of thehand due to insulating inner glove 200. A patient may massage conductivegel into the finger portions of conductive glove 300 to improve theelectrical conductivity between the surface of the skin and conductiveglove 300. Conductive glove 300 is flexible so it can be worn.Conductive glove 300 could be made entirely of a conductive material,but would typically be made of a suitable combination of conductive andnon-conductive materials, such as a silver plated nylon.

Referring to FIG. 3C, a protective outer glove 400 is worn on the handof the patient, over the previously fit conductive glove 300 andinsulating inner glove 200. Protective outer glove 400 completely coversconductive glove 300 to protect conductive glove 300 against damage andto insulate the outer surface of conductive glove 300.

Referring back to FIG. 3B, conductive glove 300 has a conductivehook-and-loop fastener 301 (such as a VELCRO brand hook-and-loopfastener) attached to the top, exterior wrist-area of conductive glove300. Conductive hook-and-loop fastener 301 is in electrical contact withconductive glove 300, and is positioned to make contact with acomplementary conductive hook-and-loop fastener of protective outerglove 400. Other conductive releasable mechanisms may be used in placeof the conductive hook-and-loop fasteners, but would typically alloweasy connection and disconnection when desired, while being sufficientlywell connected to not become undone with ordinary movement.

Protective outer glove 400 has a lead wire connection 401 positioned onthe back of the glove, in the area covering the patient's wrist. Leadconnection 401 releasably connects to the glove connection 108 of leadwire 104 (shown in FIG. 1). Lead connection 401 may be a metal snap orsome other releasable conductive mechanism that is easily removedmanually when desired without tools. Lead connection 401 passes throughthe fabric of protective outer glove 400 and is in electrical contactwith a conductive hook-and-loop fastener 402 (shown in FIG. 4A) mountedon the inside surface of protective outer glove 400. FIG. 4A illustratesprotective outer glove 400 with a portion of the fabric turnedinside-out, exposing conductive hook-and-loop fastener 402, as attachedto the inner surface of the glove.

FIG. 4B shows an exploded, partial cross-sectional right side view ofthe multi-layer glove system as worn by the patient on the right hand(the layers of the glove system are separated for viewing convenience).Conductive hook-and-loop fastener 402 is positioned to make electricalcontact with conductive hook-and-loop faster 301 of conductive glove 300when all three glove layers are worn. Insulating inner glove 200 is wornclosest to the skin. Conductive glove 300 is worn over insulating innerglove 200. Protective outer glove 400 is worn over both other gloves.Thus, an electrical connection is established between the finger portion201 and lead wire 104 by way of conductive glove 300, the complementaryconductive hook-and-loop fasteners 301 and 402, wire connection 401, andglove connection 108.

Protective outer glove 400 may be made from any fabric traditionallyused to manufacture gloves. It may also have a coating on its innersurface to prevent the conductive gel used with conductive glove 300from saturating the fabric of protective outer glove 400. Protectiveouter glove 400 can be made, for example, from spandex fiber with aninner rubberized coating.

This embodiment of the multi-layer glove system has a number of usefulfeatures. Protective outer glove 400 prevents conductive glove 300 frommaking accidental electrical contact with areas of the patient's skinother than the finger portions as described above. The patient mayhandle objects or use his or her hands during treatment withoutinterfering with the electrical signal. In addition, the inner surfacecoating contains the conductive gel to inhibit the gel from beingdeposited on other areas of the patient's skin, the patient's clothing,and objects that the patient may handle during treatment. Similarly, theinner surface coating also helps prevent the conductive gel fromdrying-out during treatment, thereby prolonging the effectiveness of thegel.

The complementary conductive hook-and-loop fasteners also perform asafety function. When the patient removes the protective outer glove,the electrical connection between the complementary conductivehook-and-loop fasteners is broken automatically and without additionalaction being required. Thus, the conductive glove is de-energized whenthe protective outer glove is removed. Should the patient accidentallyleave the signal generator on before removing the glove system, thisfeature prevents the patient from accidentally completing the electricalcircuit with an area of the skin other than the desired treatment area.

The glove system can isolate the finger portions as a treatment area. Itis believed that isolating the finger portions as a treatment area iseffective in treating symptoms associated with diseases of the joints,such as rheumatoid arthritis of the hand. It is theorized that isolationof the finger portions as a treatment area allow for superior ionconduction through the cartilage of the treated joints, therebyincreasing the current through the joints. The increased currentproduces an increased electrical field in the cartilage, which isbelieved to mimic the electrical potentials found in healthy cartilagethat cause the body to produce new cartilage.

Although the beneficial effects are thought to decrease as the distancefrom the treatment area increases, the glove system may be effective intreating aliments of the elbow. Use of the medical device disclosedherein is believed to reduce the patient's evaluation of pain andsymptoms in the treated joints and increase the patient's evaluation offunction in the treated joints. The ability of the glove system toisolate the fingertips may also have applications in traditionaltranscutaneous electrical nerve simulation therapy.

Turning to the electrical components and waveforms, FIG. 5 is a frontplan view of an embodiment of a signal generator 50. Signal generator 50may be a device such as the one described in U.S. Pat. No. 5,273,033 toHoffman. Signal generator 50 may also be a traditional commerciallyavailable transcutaneous electrical nerve stimulator. Signal generator50 is a battery powered electrical stimulator, which produces aspecific, periodic, spike shaped electrical signal to the multi-layerglove system at the treatment site. Suitable sources of power include analkaline battery or a Nickel Metal Hydride battery. Signal generator 50has at least one treatment channel, which includes a complete electricalcircuit when the signal generator output is connected to the arm wrapand multi-layer glove system described above.

Signal generator 50 has an LCD display 501, which allows the patient toread information concerning the level of treatment, duration oftreatment, battery status, signal generator status, and otherinformation. Signal generator 50 has an On/Off button 502 which allowsthe patient to turn the unit on and off, a stimulation increase button503 that may be pressed to increase the level of electrical stimulationproduced by a treatment channel of signal generator 50, and astimulation decrease button 504 that may be pressed to change the levelof electrical stimulation produced with suitable thresholds. Signalgenerator 50 may have multiple treatment channels, each having a set ofstimulation increase and decrease buttons. The generator could haveselectable alternative waveforms.

A function button 505 may be pressed to display the treatment time onLCD 501. A battery button 506 may be pressed to display the batterycharge level on LCD 501.

FIG. 6 is a bottom plan view of the signal generator of FIG. 5. Signalgenerator has a lead wire connection 507, which connects to signalgenerator connection 106 of lead wire 104 (shown in FIG. 1). Lead wireconnection 507 may be a keyed shape, complementary to the shape ofsignal generator connection 106. This ensures proper connection to thesignal generator and proper polarity between the treatment electrode andreturn electrode. In one embodiment, signal generator 50 has anadditional treatment channel, in which case, an additional lead wireconnection 508 is provided.

FIG. 8 is a voltage waveform illustrating the characteristics of anexemplary electrical treatment signal produced by the signal generator50 under no load conditions. In one embodiment, the electrical treatmentsignal is a voltage-sourced, spike-shaped, monophasic, and asymmetricalDC signal. The frequency is fixed at 100±5 Hz. The voltage range is 0-12volts at the peak. The voltage pulse width is 1.8 ms at the 10% point ofpeak and 0.64 ms at the 50% point of peak. The current output range is0-24 mA at 500 ohms resistive load, with an average of 0.2 mA at 500ohms resistive load. The current pulse width is 1.8 ms at the 10% pointof peak and 0.64 ms at the 50% point of peak, both at 500 ohms resistiveload. The maximum output charge is 20 μC into a load of 500 ohms. Thevoltage of the electrical treatment signal may be adjusted by thepatient so the signal is subsensory to the patient. Treatment could beapplied over many hours, and could be applied overnight. The selectedwaveform would typically not provide much heat to the treated area.

As will be realized, the inventions are capable of other and differentembodiments and its several details may be capable of modifications invarious respects, all without departing from the invention as set out inthe appended claims. For example, the treatment signal produced bysignal generator 50 may vary from the waveform described above, or themulti-layer glove system may be used with a current-sourced electricalsignal generator, such as a traditional transcutaneous electrical nervestimulator. Accordingly, the drawings and description are to be regardedas illustrative in nature and not in a restrictive or limiting sensewith the scope of the application being indicated in the claims.

1. A medical device comprising: a lead wire for providing an electricalsignal to at least one portion of a patient's body, the lead wire havingat least two electrically conductive paths for the creation of anelectrical circuit, the electrical circuit including at least a portionof the patient's body; a non-invasive conductive electrode forcontacting the patient's skin; a multi-layered glove system, the glovesystem having an electrically insulating layer and a non-invasiveconductive layer, the electrically insulating layer insulating a portionof a hand and not the entirety of the hand of the patient from contactwith the non-invasive conductive layer, the non-invasive conductivelayer having an inner surface and an outer surface, the inner surfacemaking electrical contact with at least a portion of the hand of thepatient; a signal generator for producing a desired electrical signal inat least a portion of the patient's body, the signal generator beingreleasably electrically coupled to the non-invasive conductive electrodevia one of the electrically conductive paths of the lead wire, and thesignal generator being releasably electrically coupled to thenon-invasive conductive layer via another of the electrically conductivepaths of the lead wire.
 2. The medical device of claim 1, wherein theelectrically insulating layer is designed such that when worn on a hand,the skin of the fingers and thumb distal to the metacarpophalangealjoints are not covered by the electrically insulating layer, and themetacarpophalangeal joints, the back of the hand, and the palm of thehand are covered by the electrically insulating layer.
 3. The medicaldevice of claim 1, wherein the non-invasive conductive electrodecontacts the surface of the skin about halfway between the elbow and theshoulder.
 4. The medical device of claim 1, wherein the desiredelectrical signal is a periodic signal selected to rebuild cartilage ofa joint when applied to a joint of the human body.
 5. The medical deviceof claim 1, wherein the desired electrical signal is a voltage-sourced,spike-shaped, monophasic, repeating, and asymmetrical DC signalcharacterized by an exponential decay and having a frequency of about 95to 105 hertz, a voltage of about 0 to 12 volts at the peak, a voltageand current pulse width of about 1.8 ms at the 10% point of peak andabout 0.64 ms at the 50% point of peak, and a current of about 0 to 24mA at 500 ohms resistive load with an average of about 0.2 mA at 500ohms resistive load.
 6. The medical device of claim 1, wherein thedesired electrical signal is subsensory.
 7. The medical device of claim1, wherein at least a portion of the electrically insulating layerincludes one of vinyl, neoprene, or polyurethane.
 8. The medical deviceof claim 1, wherein at least a portion of the non-invasive conductivelayer includes silver plated nylon.
 9. A medical device comprising: amulti-layered glove system having an electrically insulating layer and anon-invasive conductive layer for use over the electrically insulatinglayer, the insulating layer formed to cover and insulate a portion of awearer's hand and not the entirety of the hand from contact with thenon-invasive conductive layer to leave an exposed portion, thenon-invasive conductive layer having an inner surface and an outersurface, the inner surface making electrical contact with at least partof the exposed portion; and a conductive lead for allowing a lead wireto be manually connected and disconnected from the non-invasiveconductive layer.
 10. The medical device of claim 9, wherein theelectrically insulating layer is designed such that when worn on a hand,the skin of the fingers and thumb distal to the metacarpophalangealjoints are not covered by the electrically insulating layer, and themetacarpophalangeal joints, the back of the hand, and the palm of thehand are covered by the electrically insulating layer.
 11. The medicaldevice of claim 9, further comprising a conductive electrode forcontacting the surface of the skin below the shoulder.
 12. The medicaldevice of claim 9, where the non-invasive conductive layer receives adesired electrical signal selected to rebuild cartilage of a joint whenapplied to a joint of the human body.
 13. The medical device of claim 9,wherein at least a portion of the electrically insulating layer includesone of vinyl, neoprene, or polyurethane.
 14. The medical device of claim9, wherein at least a portion of the non-invasive conductive layerincludes silver plated nylon.
 15. A method comprising: covering aportion of a hand and not the entirety of the hand of a patient with anelectrically insulating layer; covering the hand of the patient andelectrically insulating layer with a non-invasive conductive layer suchthat the non-invasive conductive layer makes electrical contact with atleast a portion of the hand not covered by the electrically insulatinglayer; contacting the patient's skin with a non-invasive conductiveelectrode; and providing a desired electrical signal in at least aportion of the patient's body by electrically connecting thenon-invasive conductive layer and non-invasive conductive electrode to asignal generator.
 16. The method of claim 15, wherein the electricallyinsulating layer is designed such that when worn on a hand, the skin ofthe fingers and thumb distal to the metacarpophalangeal joints are notcovered by the electrically insulating layer, and themetacarpophalangeal joints, the back of the hand, and the palm of thehand are covered by the electrically insulating layer.
 17. The method ofclaim 15, wherein the non-invasive conductive electrode contacts thesurface of the skin about halfway between the elbow and the shoulder.18. The method of claim 15, wherein the desired electrical signal is aperiodic signal selected to rebuild cartilage of a joint when applied toa joint of the human body.
 19. The method of claim 15, wherein thedesired electrical signal is a voltage-sourced, spike-shaped,monophasic, repeating, and asymmetrical DC signal characterized by anexponential decay and having a frequency of about 95 to 105 hertz, avoltage of about 0 to 12 volts at the peak, a voltage and current pulsewidth of about 1.8 ms at the 10% point of peak and about 0.64 ms at the50% point of peak, and a current of about 0 to 24 mA at 500 ohmsresistive load with an average of about 0.2 mA at 500 ohms resistiveload.
 20. The method of claim 15, wherein the desired electrical signalis subsensory.
 21. The method of claim 15, wherein at least a portion ofthe electrically insulating layer includes one of vinyl, neoprene, orpolyurethane.
 22. The method of claim 15, wherein at least a portion ofthe non-invasive conductive layer includes silver plated nylon.